Cooling Sun Block Compression Arm Sleeve Sun Protection Athletic Covers 8 Colors (military) Bike Arm Sleeve used for protecting arm from UV rays and it's cool more than bare skin It can keep you dry and cool in the hot condition and warm in cold condition. Sun Protection Athletic Covers. Stretch material and no slipping down, quickly dry and remover easily Material : Tactel 80%, Lycra 20% General adult size (About 380mm X 105~85mm Elastic material ) Random characters are printed on the cuffs.